1. Field of the Invention
The present invention relates to a seat and, more particularly, to a structure for pushing up a seat cushion employed in a seat for seating an occupant of a vehicle so that a part of the seat cushion is pushed up in response to the operation of a seatbelt system designed to protect the occupant in emergency situation of the vehicle, thereby allowing the occupant's body to be restrained more reliably.
2. Description of the Related Art
Seatbelt systems for vehicles are generally arranged such that an occupant fastens a webbing and, when an emergency situation of the vehicle occurs, the occupant's body is restrained by this webbing.
At the time of an emergency situation of the vehicle, it is preferable to restrain the upper part and waist of the body of an occupant so that his body is prevented from moving toward the front end of the vehicle by a substantial extent.
In a three-point type seatbelt system, the upper part of the body of an occupant is restrained by a shoulder webbing, and there is therefore no risk of the occupant's body moving forwardly to a substantial degree. The waist of the occupant is restrained by a lap webbing and, in order to prevent his waist from moving forwardly to a substantial extent when an emergency situation of the vehicle occurs, the anchor point of the lap webbing needs to be disposed as close to the rear end of the vehicle as possible. In the case where an anchor member is provided on the seat, however, the place where the anchor point can be disposed is limited.